I did before to send my request.
There is a +1 to a pretty old question, before my update. There was one update on the tablet to move to 4.4.2 then another update in september 2014. That's why even if it's OK for first version of 4.4.2, maybe it's not for the new version in september.
Also, I'm sorry but I'm not sure what +1 mean for a question. I guess it's someone who also what to known the answer of the question.
But I tested Lollipop ROM (Official CyanogenMod 12) and the Logitech K400r works like a charm.
I would prefer to stay on Stock ROM as this is not my tablet but I'm OK with this solution.
FYI, I had a lot of difficulties to install TWRP (needed to go back to 4.2.2) and I had also some issue with wifi authentication (needed to move to WPA2-PKI)